The present invention relates to an auxiliary helicopter rotor.
The auxiliary rotors of advanced design helicopters usually comprise a center hub having two or more peripheral blades, each of which presents a root with two bores on the end facing the hub.
On know rotors of the aforementioned type, each blade is connected to the hub by means of an intermediate connecting element located between the respective blade and the hub, and substantially coaxial with the blade. At one end, the said connecting element presents a fork engaged by the respective blade root, and connected to the blade by means of two pins. At the other end, each connecting element is tubular in shape, and presents two axial appendixes defining a bore for hinging the blade-connecting element assembly to the hub by means of a spherical joint, and a lateral appendix for connecting a pitch-change lever.
For each said blade, the hub presents a substantially radial leaf located substantially in the plane of the respective said blade. Each said leaf extends inside the tubular end of the respective said connecting element, and is connected to the same be means of an axial elastomeric bearing.
Clearly, therefore, on known types of auxiliary rotors of the aforementioned type, connection of the blades to the hub is extremely complex, due to the presence of the said connecting elements. What is more, the strength required of the said connecting elements contributes greatly towards increasing the total weight of the auxiliary rotor as a whole.